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Submission #577700

# Submission time Handle Problem Language Result Execution time Memory
577700 2022-06-15T08:14:33 Z vanic Event Hopping (BOI22_events) C++14
10 / 100
 1500 ms 53244 KB 
#include <cstdio>
#include <cmath>
#include <algorithm>
#include <vector>
#include <set>
#include <map>
#include <cstring>
#include <queue>
 
using namespace std;
 
const int maxn=1e5+5, Log=18, pot=(1<<Log);
 
vector < int > svi;
 
void query(int L, int D, int x, int l, int d){
	if(L>=l && D<=d){
		svi.push_back(x);
		return;
	}
	if((L+D)/2>=l){
		query(L, (L+D)/2, x*2, l, d);
	}
	if((L+D)/2+1<=d){
		query((L+D)/2+1, D, x*2+1, l, d);
	}
}
 
 
pair < int, int > a[maxn];
set < int > s;
map < int, int > m;
int dist[pot*2];
int d[maxn];
vector < pair < int, int > >  ms[pot*2];
 
void precompute(){
	for(int i=2; i<pot*2; i++){
		ms[i].push_back({i/2, 0});
	}
}
 
void bfs(int x){
	memset(dist, -1, sizeof(dist));
	memset(d, -1, sizeof(d));
	queue < int > q1, q2;
	q1.push(a[x].second+pot);
	dist[a[x].second+pot]=0;
	d[x]=0;
	int tren=0;
	while(!q1.empty()){
		while(!q1.empty()){
			x=q1.front();
			q1.pop();
			for(int i=0; i<(int)ms[x].size(); i++){
				if(ms[x][i].second){
					if(dist[ms[x][i].first]==-1){
						dist[ms[x][i].first]=tren+1;
						q2.push(ms[x][i].first);
					}
					if(d[ms[x][i].second]==-1){
						d[ms[x][i].second]=tren+1;
					}
				}
				else{
					if(dist[ms[x][i].first]==-1){
						dist[ms[x][i].first]=tren;
						q1.push(ms[x][i].first);
					}
				}
			}
		}
		swap(q1, q2);
		tren++;
	}
}
 
int main(){
	precompute();
	int n, q;
	scanf("%d%d", &n, &q);
	for(int i=1; i<=n; i++){
		scanf("%d%d", &a[i].first, &a[i].second);
		s.insert(a[i].second);
	}
	int br=0;
	
	for(auto it=s.begin(); it!=s.end(); it++){
		m[*it]=br;
		br++;
	}
	set < int >::iterator it;
	for(int i=1; i<=n; i++){
		it=s.lower_bound(a[i].first);
		a[i]={m[*it], m[a[i].second]};
//		cout << a[i].first << ' ' << a[i].second << endl;
		query(0, pot-1, 1, a[i].first, a[i].second);
		while(!svi.empty()){
//			cout << "moji " << svi.back() << endl;
			ms[svi.back()].push_back({a[i].second+pot, i});
			svi.pop_back();
		}
	}
	int x, y;
	for(int i=0; i<q; i++){
		scanf("%d%d", &x, &y);
		bfs(x);
		if(d[y]==-1){
			printf("impossible\n");
		}
		else{
			printf("%d\n", d[y]);
		}
	}
	return 0;
}

Compilation message

events.cpp: In function 'int main()':
events.cpp:81:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   81 |  scanf("%d%d", &n, &q);
      |  ~~~~~^~~~~~~~~~~~~~~~
events.cpp:83:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   83 |   scanf("%d%d", &a[i].first, &a[i].second);
      |   ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
events.cpp:106:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  106 |   scanf("%d%d", &x, &y);
      |   ~~~~~^~~~~~~~~~~~~~~~

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 34 ms 31444 KB Output is correct
2 Execution timed out 1575 ms 41628 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 35 ms 31448 KB Output is correct
2 Correct 34 ms 31412 KB Output is correct
3 Correct 48 ms 31548 KB Output is correct
4 Correct 45 ms 31436 KB Output is correct
5 Correct 47 ms 31544 KB Output is correct
6 Correct 47 ms 31536 KB Output is correct
7 Correct 53 ms 31564 KB Output is correct
8 Correct 43 ms 31620 KB Output is correct
9 Correct 42 ms 31436 KB Output is correct

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 35 ms 31448 KB Output is correct
2 Correct 34 ms 31412 KB Output is correct
3 Correct 48 ms 31548 KB Output is correct
4 Correct 45 ms 31436 KB Output is correct
5 Correct 47 ms 31544 KB Output is correct
6 Correct 47 ms 31536 KB Output is correct
7 Correct 53 ms 31564 KB Output is correct
8 Correct 43 ms 31620 KB Output is correct
9 Correct 42 ms 31436 KB Output is correct
10 Correct 37 ms 31388 KB Output is correct
11 Correct 43 ms 31372 KB Output is correct
12 Correct 52 ms 31544 KB Output is correct
13 Correct 55 ms 31540 KB Output is correct
14 Correct 48 ms 31472 KB Output is correct
15 Correct 43 ms 31472 KB Output is correct
16 Correct 47 ms 31572 KB Output is correct
17 Correct 46 ms 31624 KB Output is correct
18 Correct 45 ms 31416 KB Output is correct
19 Execution timed out 1573 ms 32484 KB Time limit exceeded
20 Halted 0 ms 0 KB -

Subtask #4
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 35 ms 31448 KB Output is correct
2 Correct 34 ms 31412 KB Output is correct
3 Correct 48 ms 31548 KB Output is correct
4 Correct 45 ms 31436 KB Output is correct
5 Correct 47 ms 31544 KB Output is correct
6 Correct 47 ms 31536 KB Output is correct
7 Correct 53 ms 31564 KB Output is correct
8 Correct 43 ms 31620 KB Output is correct
9 Correct 42 ms 31436 KB Output is correct
10 Correct 45 ms 31440 KB Output is correct
11 Correct 44 ms 31444 KB Output is correct
12 Correct 47 ms 31460 KB Output is correct
13 Correct 45 ms 31456 KB Output is correct
14 Correct 46 ms 31484 KB Output is correct
15 Correct 43 ms 31488 KB Output is correct
16 Correct 50 ms 31528 KB Output is correct
17 Correct 50 ms 31564 KB Output is correct
18 Correct 44 ms 31460 KB Output is correct
19 Correct 1482 ms 41616 KB Output is correct
20 Correct 786 ms 41660 KB Output is correct
21 Correct 819 ms 42300 KB Output is correct
22 Correct 430 ms 41616 KB Output is correct
23 Correct 1383 ms 53244 KB Output is correct
24 Execution timed out 1573 ms 52936 KB Time limit exceeded
25 Halted 0 ms 0 KB -

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1583 ms 41616 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 34 ms 31444 KB Output is correct
2 Execution timed out 1575 ms 41628 KB Time limit exceeded
3 Halted 0 ms 0 KB -